Insecticide Toxicologu Flashcards
How did DDT act on insects?
Interferes with sodium channel in activation of insect nerves.
Do carbamates in insects target the synapse, neuron or axon?
Do carbamates in insects target the synapse, neuron or axon?
What effects do the following neurotransmitters have in insect CNS (inhibitory or excitatory)?
- ACh
- Glutamate
- GABA
- Excitatory (same as humans)
- Inhibitory (different from humans)
- Inhibitory (same as humans)
What are transgenic crops? How do they apply to insecticides?
Crops with transplanted genes that produce insecticidal compounds.
E.g. ∂-endotoxin from Bacillus Thurigenesis
Pyrethrum is isolated from which flower?
Chrysanthemum
What effects do the following neurotransmitters have in insect PeriphNS (inhibitory or excitatory)?
- Glutamate
- GABA
- Excitatory
2. Inhibitory
An insect dosed with pyrethroid has what effects on the h and m gate?
Slowing effects.
Do Pyrethrins/Pyrethroids in insects target the synapse, neuron or axon?
Neuron and axon.
What is the safety factor used for insecticides?
LD50 [Rats] / LD50 [insects]
What is the treatment of organophosphate poisoning?
Atropine. Blocks M receptor, relieves parasympathetic symptoms.
What is the difference between a Pyrethrin and a Pyrethroid?
Pyrethroids are synthetic.
What are the types of resistance that can develop in insects?
Metabolic
Target-site insensitivity
Penetration resistance
Do organochlorines in insects target the synapse, neuron or axon?
The neuron and axon.
Baculoviruses have an upside and downside of what?
Upside: High specificity
Downside: Long kill time. The insect could have already eaten the plant before it finally dies from exposure.
Why are mammals safe from pyrethrins?
No bioaccumulation because it is easily hydrolysed by cholinesterases.
DDT was what type of insecticide?
Organochlorine.
Do organophosphates in insects target the synapse, neuron or axon?
Synapse.
Which neuroactive insecticides make up the biggest market share of insecticides?
Pyrethroids.
The ideal insecticide has what characteristics?
- Effective
- Selective
- Non-persistent
- Affordable
- Effective in resistant strains
- Usage does not tend to lead to resistance.
There are four generations of pyrethroids, which are photounstable.
1st and 2nd.
Why does insect resistance tend to occur with pesticides?
Long term use.
Few chemicals to choose from.
Restricted number of nervous system targets.
What are transgenic crops? How do they apply to insecticides?
Crops with transplanted genes that produce insecticidal compounds.
E.g. ∂-endotoxin from Bacillus Thurigenesis
